The annual Sports Illustrated Swimsuit Issue features some of the world's most famous models in their two-pieces. Bar Refaeli wore a bikini for a spread with some well-known athletes like Rafael Nadal, Michael Phelps, and Chris Paul. Chrissy Teigen, Anne V, and Irina Shayk also show skin in the magazine. Click through to see highlights from SI's latest, which features Kate Upton on the cover, and make sure to check out all the 2012 Sports Illustrated bikini pictures!